Investigation on Arsenic−Antimony‐ and Arsenic−Bismuth Bond Containing Interpnictogen Chain Molecules

The stepwise synthesis of novel As−Sb and As−Bi bond containing molecules is described. The binary interpnictogen compounds t Bu 2 EAs(H) t Bu (E=Sb ( 1 ), P ( 4 )) were prepared by reaction of t Bu 2 ECl with t BuAs(H)Li ⋅ 1,4‐dioxane. Subsequent lithiation yields the dimeric compounds [ t Bu 2 EAsLi(thf) t Bu] 2 (E=Sb ( 2 ), E=P ( 5 )). Compound 2 as well as t Bu 2 SbAs( t Bu)SiMe 3 ( 3 ) are not suitable as synthons for longer chains due to non‐selective reactions. In contrast, compound 5 was successfully used for the preparation of chains with three ( t Bu 2 PAs( t Bu)E′ t Bu 2 (E′=P ( 6 ), As ( 7 ), Sb ( 8 ), Bi ( 9 )) and even four adjacent group 15 elements ( t Bu 2 PAs( t Bu)E′′ ( t Bu)N(H) t Bu (E′′=P ( 12 ), As ( 13 ), Sb ( 14 )). Finally, the diarsane ( t Bu 2 PAs t Bu) 2 ( 15 ) was synthesised by reaction of 5 with 1,2‐dibromoethane. The obtained compounds were characterised by mass spectrometry, multinuclear NMR spectroscopy, IR spectroscopy and by single crystal X‐ray diffraction in the case of 2 , 5–9 and 12 – 15 .